Escola de Engenharia de Lorena, Universidade de São Paulo, CP. 116, Lorena, São Paulo, Brazil.
J Hazard Mater. 2010 Jan 15;173(1-3):630-6. doi: 10.1016/j.jhazmat.2009.08.131. Epub 2009 Sep 1.
A type of ZrO(2).nH(2)O was synthesized and its Cr(VI) removal potential was investigated in this study. The kinetic study, adsorption isotherm, pH effect, thermodynamic study and desorption were examined in batch experiments. The kinetic process was described by a pseudo-second-order rate model very well. The Cr(VI) adsorption tended to increase with a decrease of pH. The adsorption data fitted well to the Langmuir model. The adsorption capacity increased from 61 to 66 mg g(-1) when the temperature was increased from 298 to 338 K. The positive values of both Delta H degrees and DeltaS degrees suggest an endothermic reaction and increase in randomness at the solid-liquid interface during the adsorption. Delta G degrees values obtained were negative indicating a spontaneous adsorption process. The effective desorption of Cr(VI) on ZrO(2).nH(2)O could be achieved using distilled water at pH 12.
本研究合成了一种 ZrO(2).nH(2)O，并研究了其去除六价铬的潜力。通过批量实验考察了动力学研究、吸附等温线、pH 效应、热力学研究和脱附。动力学过程很好地用拟二级速率模型来描述。Cr(VI)的吸附随着 pH 的降低而增加。吸附数据很好地符合朗缪尔模型。当温度从 298 K 升高到 338 K 时，吸附容量从 61 mg/g 增加到 66 mg/g。Delta H 度和 Delta S 度的正值表明吸附过程是吸热的，固液界面上的无序度增加。获得的 Delta G 度值为负，表明吸附过程是自发的。使用 pH 值为 12 的蒸馏水可以有效地将 Cr(VI)从 ZrO(2).nH(2)O 上解吸。
